Winding elastic thread



Sept. 28, 1954 LONG 2,690,047

WINDING ELASTIC THREAD Filed Jan. 23, 1952 INVENTOR. RA L PH 5. L ON 6 Patented Sept. 28, 1954 UNITED STATES; PATENT OFFICE WINDING ELASTIC THREAD.

R lnh B. Lo a Reanq i or o Amecan Viscose Corporation, Wilmington, DeL, a corporation of Delaware Application January 23, 1952, Serial No. 261,869.

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This invention relates to. the manufacture and handling of elastic filamentary materials. More particularly it relates to a novel and convenient method of detecting irregularities and weaknesses. in elastic filamentary materials wherein the. necessity of a separate step of inspection in the manufacture thereof is eliminated.

At the outset of, the description of this inven-.- tion, it is to be emphasized that, although the; disclosure is presented in connection with elastic strand covering apparatus, such disclosure is by way of example only. The subject matter of the invention primarily involves a novel and convenient means for testing the strength and resilience of the elastic strand. Thus, the protective covering apparatus between the elastic core source and the tension-applying roller meanshereinafter described more fully could be eliminated without departing substantially from the spirit or scope of the invention. The disclosure is made in connection with protective covering apparatus merely to emphasize the ready and convenient application of this method of inspection to a typical filamentary manufacturing process.

It is therefore a principle of this invention to detect and discover in the manufacture of elastic filamentary materials weak portions in the elastic filament or core.

It is an ancillary object of this invention to detect irregularities in the filamentary material and yet avoid the necessity of a separate inspection thereof in the manufacturing process.

Other objects and advantages of the invention will be apparent from the following description.

In the accompanying drawing which is illustrative of a preferred embodiment of the invention, the pretwisted elastic core 3 of filamentary material which is to be supplied with a protective covering and tested for strength and resilience is shown wrapped on a suitable bobbin or spool 4. The rate at which the core 3 is unwound from the spool 4 is controlled by a roller 5 which is driven on shaft 6 by a suitable source of power, not shown on the drawing, and which frictionally engages the spool of filamentary material.

From the spool 4 the core is directed upwardly through the hollow spindle 1 between the niproll'ers 8 and 9, through the traversing mechanism 1 l and ultimately to the collecting means l0; The collecting means Ill and the nip roller 9 are separately driven at related speeds as will be hereinafter more fully described by means of shaft [3 and friction roller M which are driven by" independently controlled power means not 2 shown. n the aw ng elthe eh h le ee ea i disc osed t e draw n th t m of a 1 .1 21 9. i? under hat an we venient collecting means may be employed with: out ep t n from h? p t Q 1. Q the vention.

The covering yarn l5 helically applied to the elastic core it from a package Iii which is mounted on and rotates with the spindle l. Belt nds etwee a u l I m un ed the. i e a a Suitable power sou e not how and provides a means for rotating the spindle and package of covering yarn about the upwardly moving core. Flier guide l9 controls the helical angle ofapplication of the covering yarn i5 upon the core 3 and also serves to prevent the covering yarn from contacting and possibly foulm he pp e of e cov rin y rn p ckage- Thespindle l and the package of covering yarnlt are mounted upon the horizontal extension 2!} of the machine frame.

Although the elastic core- 3 has been disclosedas being originally pretwisted a given direction, it is to be understood that the yarn is ultimately balanced due to the twisting tendency of the GP? positely helically appliedv covering I5. It is to be also understood that this invention may be practiced equally as well upon an originally balanced core by merely applying thereto a pair of oppositely wound wrapping's instead of the single wrapping shown in the drawing. In thisway the opposite twisting. tendencies of the individual covering operations efiectively counterbalance each other.

As is customary in the manufacture of covered elastic yarn, the covering material ['5' is applied.

while the elastic core 3 is placed under tension.

In. this way the covering is applied to the core in a more proficient manner and at the same time the ultimate elastic quality of the yarn is carefully controlled. In the construction of the apparatus shown herein the desired tension upon the elastic core during the covering operation is maintained by passing the covered yarn between the nip rollers 8 ands at a sufiiciently higher rate than the rate at which the elastic core unwinds from the spool 42 such that the core is stretched a desired amount. The covered yarn then passes from between nip rollers through the: traversing mechanism I I about the collecting drum lc with substantially no tension on the core. Since the tension upon the elastic core is relaxed when the core proceeds beyond the nip: rollers 8 and 9, the elastic qualities of the core cause it to contract considerably. Thus; to prevent the pres 3 ence of tension upon the core between rollers 8 and 9; and collecting drum ID, the peripheral velocity of collecting drum i6 must be properly reduced in comparison to the peripheral speed of the nip rollers to compensate for the contracting core.

When these peripheral speeds are properly adjusted for normal operating conditions, it has been noted that observation of the relative amount of slack in the covered yarn between the nip rollers and the collecting reel provides a clear indication of the presence or absence of irregularities in the structure of the elastic core.

As long as no weak spots or irregularities are encountered in the core, it stretches uniformly between the source and the nip rollers and a constant amount of slack is maintained along the untensioned portion of the core between the nip rollers and the collecting means. However, when a weak spot of reduced cross section or other irregularity is encountered in the core, much of the overall elongation between the source and the nip rollers is localized in the weak spot and the adjacent normal core sections are stretched proportionately less. Thus, when the tension upon the adjacent normal core sections is relaxed, the accompanied contraction is also less and therefore insufficient to permit the collecting drum I to keep pace with the more rapidly r0- tating nip rollers 8 and 9. Consequently the slack I'2 therebetween momentarily increases noticeably. In this way the relative amount of slack in the untensioned core between the nip rollers and the collecting reel provides a convenient and reliable means for checking the quality of the elastic core.

A graduated indicating means 2! is provided adjacent the untensioned portion of the elastic filamentary material between the nip rollers 8 and 9 and the collecting reel [0. By means of this indicator changes in slack [2 are made readily apparent. Other convenient forms of indicators could be substituted for the graduated scale indicating means shown in the drawing without departing from the spirit of the invention. It is to be also pointed out that changes in slack l2 can be satisfactorily observed without reference to any indicating means. Thus, the indicating means 21 could be also eliminated without departing from the spirit or scope of the invention.

It is to be emphasized again that the disclosed means for inspecting the tensile and resilient qualities of an elastic filament can be equally as well employed where the covering apparatus is eliminated by applying a tension between an unwinding spool and a pair of nip rollers, passing the elastic filament on to a collecting reel with substantially no tension applied thereto and noting the relative amount of slack adjacent the untensioned portion of the filamentary material.

While preferred embodiments of the invention have been disclosed, the description is intended to be illustrative only and it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A method of detecting irregularities in an elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point, relaxing the tension on the filamentary material as it progresses between the intermediate point and the point of collection, and observing changes in the amount of slack along the relaxed portion of the filamentary material.

2. A method of detecting irregularities in an elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point by increasing its surface velocity at the intermediate point, relaxing the tension between the intermediate point and the point of collection, and observing changes in slack along the relaxed portion of the filamentary material.

3. A method of detecting irregularities in an elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point by increasing its surface velocity at the intermediate point, relaxing the tension on the filamentar material as it progresses between the intermediate point and the point of collection maintaining under normal conditions a constant amount of slack in the untensioned filamentary material between the intermediate point and the point of collection, and observing changes in the amount of slack therebetween.

i. A method of detecting irregularities in an elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point, relaxing the tension on the filamentary material between the intermediate point and the point of collection, controllin the progress of material at the intermediate point and the point or" collection to maintain under normal conditions a constant slack therebetween, and observing the changes of the slack.

5. A method of processing elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point by increasing its surface velocity at the intermediate point, applying helical wrappings of covering material about the filamentary material in its tensioned condition, relaxing the tension on the filamentary material between the intermediate point and the point of collection, and observing changes in the amount of slack along the relaxed portion of the filamentary material.

6. A method of processing elastic filamentary material comprising causing the filamentary material to progress from a source through an intermediate point to a point of collection, applying tension to the filamentary material between the source and the intermediate point by increasing its surface velocity at the intermediate point, applying helical wrappings of covering material about the filamentary material in its tensioned condition, relaxing the tension on the filamentary material between the intermediate point and the point of collection, maintaining under normal conditions a constant amount of slack along the relaxed portion of the filamentary material, and observing changes in the amount of slack therealong.

7. Filamentary material testing apparatus comprising a source of elastic filamentary material, means for causing the filamentary material to progress from said source through an intermediate point to a point of collection, means for applying tension to the filamentary material as it progresses from the source to the intermediate point, means for relaxing the tension as the filamentary material progresses from the intermediate point to the point of collection, and a scale positioned substantially mid-way between the intermediate point and the point of collection having indicia thereon for indicating the variations in slack between said intermediate point and point of collection.

8. Filamentary material testing apparatus comprising a source of elastic filamentary material, means for causing the filamentary material to progress from the source through an intermediate point to a point of collection, means for applying tension to the filamentary material as it progresses from the source to the intermediate point, covering yarn apparatus for applying helical wrappings to the tensioned portion of the filamentary material, means for relaxing the tension as the filamentary material progresses from the intermediate point to the point of collection, and means for indicating the amount of slack in the untensioned filamentary material between the intermediate point and the point of collection.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,039,211 Subers Sept. 24, 1912 1,927,637 Gernert Sept. 19, 1933 1,961,755 Foster June 5, 1934 2,037,506 Ensinger Apr. 14, 1936 2,136,026 Shorrock Nov. 8, 1938 2,334,880 Marlow Nov. 23, 1943 2,539,954 Hunziker Jan. 30, 1951 

